耐候钢锈层的稳定化处理及锈层形成

Stabilization Treatment and Formation of Rust Layer on Weathering Steel

针对裸耐候钢保护性锈层生成时间较长及环境污染等问题,提出了一种含有合金元素的锈层稳定化处理剂,并采用喷淋的方式对耐候钢表面进行预处理。通过干湿交替腐蚀实验(CCT),对比了裸钢试样和预处理试样在模拟工业大气环境下的腐蚀规律。采用增重法评价了试样的耐蚀性;采用XRD分析了试样表面锈层的物相组成;采用SEM、电化学阻抗法(EIS)和吸水-脱水实验对锈层的致密性进行了表征和分析。结果表明,预处理试样的耐蚀性能优于裸钢试样;耐候钢经该处理剂处理后不改变耐候钢表面的腐蚀产物类型,但能够促进腐蚀产物中α-FeOOH相的生成;且经处理后耐候钢表面锈层的裂纹、孔洞等缺陷减少,致密性提高。

To speed up the formation of protective rust layer and to avoid environmental pollution,the rust stabilizer containing alloy elements was proposed and used to pretreat the samples by spraying it on the surface of weathering steel.Corrosion behaviors of bare and treated samples in simulated industrial atmosphere were studied by wet/dry cyclic corrosion test(CCT).The weatherability of the samples was evaluated by mass gain method.The composition of the rust layer on the surface of samples were analyzed by XRD.The compactness of the rust layer of samples was characterized and analyzed by SEM,electrochemical impedance spectroscopy(EIS)and absorption-dehydration method.Results show that the weatherability of the pretreated samples is better than that of the bare.The new rust stabilizer does not change the type of corrosion products on weathering steel,while can promote the formation ofα-FeOOH.Additionally,the new rust stabilizer can reduce the defects such as cracks and holes to promote the compactness of the rust layer.Therefore,the action mechanism of the new rust stabilizer is to promote the formation of theα-FeOOH in the rust layer and improve the compactness of the rust layer.